The woman, aged in her 30s, was struck by an HGV tractor unit and trailer at around 2.20am on Saturday (July 2), close to the junction with Morecambe Road, near McDonald’s.
She had been walking along the Bay Gateway with a man when the collision happened, said police.
Emergency services attended and she was taken to hospital with serious injuries, which police described as ‘life-changing’.
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The road was closed until around 7am while specialist accident investigators worked at the scene.
Police are investigating and want to hear from anybody who witnessed the collision or those who saw the pedestrian or the HGV in the moments before it happened.
The force would also like to hear from anyone who might have captured the collision on dashcam or CCTV.
Sgt Dave Hurst, of the Lancashire Police TacOps team, said: “This collision has left a woman in hospital with serious injuries and an investigation has been launched to establish exactly what occurred.
"Perhaps you saw the collision or have dashcam or CCTV showing what happened.
"The woman was walking along the Bay Gateway in company with a man when the incident took place so we are also asking anybody who drove down the road at the time of the collision to cast their minds back and see if they can remember seeing the pair.
"Similarly anybody who saw the HGV in the moments before the collision should get in touch.”
Anyone with information is asked to call police on 101, quoting log 143 of July 2.